Hello Customer (name blocked for privacy),
Yes, I believe that he probably can. The New Jersey Code of Judicial Conduct Can Be Found Here. There are a couple of provisions of the Code which might be applicable. to the conduct you describe. They are as follows:
Canon 5. A Judge Shall so Conduct the Judge's Extra-Judicial Activities as to Minimize the Risk of Conflict With Judicial Obligations
D. Financial Activities
(4) Neither a judge nor a member of the judge's family residing in the same household should accept a gift, bequest, favor, or loan from anyone except as follows:
(a) a judge may accept a gift of nominal value incident to a public testimonial; books supplied by publishers on a complimentary basis for official use; or an invitation to the judge and the judge's spouse to attend a bar-related function or activity devoted to the improvement of the law, the legal system, or the administration of justice
Canon 6. A Judge Shall Not Receive Compensation for Quasi-Judicial and Extra-Judicial Activities
A judge may not receive compensation for the quasi-judicial and extra-judicial activities permitted by this Code but may receive reimbursement of actual expenses that the judge reasonably incurred for travel, food, and lodging, provided that the source of such payments does not give the appearance of influencing the judge in the exercise of judicial duties or otherwise give the appearance of impropriety.
Canon 4. A Judge May Engage in Activities to Improve the Law, the Legal System, and the Administration of Justice
A judge, subject to the proper performance of judicial duties, may engage in the following quasi-judicial activities if in doing so the judge does not cast doubt on the judge's capacity to decide impartially any issue that may come before the court and provided the judge is not compensated therefor:
A. A judge may speak, write, lecture, and participate in other activities concerning the law, the legal system, and the administration of justice.
I think, of these provisions, the first - Canon 5(D)(4) - is probably the most relevant. As long as the fee for attending is nominal and is not really compensation, I think the gift would be fine.
I hope this answers your question.
Thomas
__________________
My answers are for informational and educational purposes only. They should not be taken as legal advice. In addition, no attorney-client relationship is created by my answers.

